Annuals and

Perennials

Ursula Schuch

School of Plant Sciences

University of Arizona, Tucson, AZ

http://ag.arizona.edu/extension/ornamentalhort

Annuals and Perennials * Herbaceous annuals

summer and winter

* Herbaceous perennials

bulbs, grasses, flowering

herbaceous plants

* Wildflowers

* Roses

Annuals

• Complete life cycle in one growing season

• Spring and fall annuals, AZ different than

other climates

• Provide instant color, long season of bloom

• Labor intensive bed preparation

• Some have high maintenance requirements

Annuals

Cool-weather plants (winter annuals)

Planted Sept. – Nov. at low elevations

Planted in spring at higher elevations

Bloom fall through spring

Heat-tolerant plants (summer annuals)

Planted after last spring frost

Bloom through summer and fall

Important winter annuals

petunia

pansy

snapdragon

alyssum

geranium

lobelia

Important summer annuals

vinca

pentas

angelonia

ipomoea

celosia

portulaca

Lantana, a perennial, is used as annual

Transition plants Sometimes planted before or after summer annuals,

don’t last an entire season

poppy anemones

ranunculus canna

chrysanthemum heliotrope

marigold coleus

kale calla lilies

gerbera

Perennials

• Last several years depending on species

• Provide seasonal color

• May die back during their off season (winter or

summer)

• Require maintenance

• Many perennials are used as annuals

Perennials

When planting perennials consider:

- Light requirement

- Good soil drainage

- Time of bloom

- Plant height

- Flower color

- Foliage color and persistence

Ornamental grasses

• Year-round interest

• Low maintenance

• Low water need

Soil preparation for annuals

Select good location

desired light levels

free of debris, weeds

loose, fertile, well-drained soil

Work soil only if not too wet or too dry.

Soil preparation for annuals

• Irrigate a day before preparing bed if soil is

dry

• Organic amendments

Add 3-4 inches on top of soil to improve

water-holding capacity, drainage, aeration

Compost, peat moss

• Incorporate into the top 8-12” of soil)

Soil preparation for annuals

Soil test to determine if fertilizer is needed

Fertilizers

Add N and S shortly before planting

1-2 lb of ammonium phosphate (16-20-0)

3 lb of sulfur per 100 square feet.

Incorporate 6-8 inches deep.

Selecting a good quality bedding plant

Good quality bedding plant: Important to ensure successful transplanting, establishment, and good performance. Plants that are too small or overgrown establish very slowly or not at all.

Selecting a good quality bedding plant

• Good quality plants: • Large enough top for the size container they grow in • Healthy green or appropriate color foliage • Regular size leaves, and no damaged leaves, stems, or

flowers • Good number of flower buds and a few open flowers • Roots visible throughout root ball with healthy white

root tips • No mat of circling roots at the base or sides of the

root ball

Planting

• Use a trowel to dig a planting hole about the size of the root ball

• Gently loosen root ball if necessary and set in planting hole

• Plant at crown level, not too high and not too deep, barely cover top of container media with soil

• Pinch off any damaged plant parts, spent flowers or yellow leaves

• Gently fill and tamp soil around plant, do not pack soil hard around the plant

Planting

• Water by hand every half hour or every section

• Do not leave tags from nursery container in the planted bed

• Mulch to a depth of 1” to 2” as appropriate for plant species

• When finished planting, water again

• Water every other day until plants can go on a regular schedule depending on weather

Follow-up care

• Set irrigation to a schedule based on the local soil conditions and weather

• Fertilize every 3-6 weeks with a balanced fertilizer to stimulate growth and flowering

• Deadhead spent flowers down to a lower branch or leaf base

• Inspect plants for insects and disease, remove dying plants, and treat as appropriate

• Inspect bed for weeds and if present remove

• Inspect if mulch needs replacement

Maintenance of perennials

• Cutting back

• Staking

• Deadheading

• Mulching

• Fertilizing

• Dividing after several years

Wildflowers

• Plant in full sun

• Plant in well drained soil

• Rake seed bed before seeding about 1 inch deep and remove weeds

• Follow directions on wildflower seed label for amount of seed to use (e.g. 0.5 lbs/1000 squ. ft.)

• Sow seed, rake in lightly and press into soil until barely covered

Wildflowers

• Water frequently until seedlings are well established, then reduce irrigation

• Control weeds and thin thick patches of seedling

• Fertilizer is not necessary unless the area is depleted of nutrients, if needed, use low N product at very low rate

• Irrigation during bloom can extend flowering

• Once flowers dry up allow to set seeds, mow to 4-6 inches to disperse seeds

Roses

Rose grades of bare root plants:

• No. 1 – three or more canes pencil thick

• No. 11/2 – two canes pencil thick

Roses can be purchased:

• Bare root

• Packaged

• Containerized

Planting roses

• Select healthy plants, immerse roots in water for a

few hours before planting

• Plant bare root roses in mid-December through

January in Southern and Western Arizona, in March

and April in Northern Arizona. Container plants can

be planted during the growing season.

• Plant in fertile, well-drained soil

• Space hybrid teas 3’ to 5’ apart, others to

accommodate final plant size.

Maintaining roses

• Irrigate deeply

• Fertilize every 4 weeks from

February until October, not in

summer

• Prune out dead and diseased wood, weak and crossing

canes. Major pruning in late winter, minor pruning as

necessary

• Moderate pruning involves leaving 5-12 canes about 18-

24 inches tall

• Dead head flowers down to the next leaf with 5 leaflets

• Learn about how to prune individual types of roses

Flower bed design examples

Height

Mass display

Design examples continued

Layered

Themed

Design continued

Perennial beds

Annual beds

Resources

University of Arizona Cooperative Extension Publications:

+ Flower Planting Guide for the Low Desert (1999)

http://ag.arizona.edu/pubs/garden/az1100.pdf

+ Rose Selection and Planting in the Low Desert (2002) http://ag.arizona.edu/pubs/garden/az1304.pdf

+ Diagnosing Problems of Roses in the Landscape (2010) http://cals.arizona.edu/pubs/garden/az1528.pdf

+ Damping – Off (2011)

http://ag.arizona.edu/pubs/crops/az1029.pdf

+ Diseases of Urban Plants in Arizona (1999)

http://ag.arizona.edu/pubs/diseases/az1124.pdf

+ Annuals for Northern Arizona above 6,000 feet (2002) http://ag.arizona.edu/pubs/garden/az1255.pdf

+ Perennials for Northern Arizona above 6,000 feet (2002) http://cals.arizona.edu/pubs/garden/az1256.pdf

+ Javelina Resistant Plants (2010)

http://ag.arizona.edu/pubs/garden/az1238.pdf

+ Recognizing and Treating Iron Deficiency in the Home Yard (2006)

http://cals.arizona.edu/pubs/garden/az1415.pdf